The Fairfax County James J. Corbalis Jr. Water Treatment Plant

On Thursday, April 26, 2012 I went up to Fairfax County near Herndon to see the Corbalis Water Treatment Plant, the newer of the two Fairfax Water treatment plants and visit with Melissa Billman, the Water Quality Laboratory & Regulatory Compliance Manager and Jeanne Bailey, the Public Affairs Officer for Fairfax Water. Combined they have more than half a century experience in Water Treatment Pants and Compliance and were kind enough to take the time to share their knowledge and experience. Fairfax Water is one of the 25 largest water supply companies in the nation supplying drinking water to 1.7 million Virginians, 900,000 of whom reside in Fairfax County. Twenty percent of all Virginians who are served by public water get their water either directly or indirectly from Fairfax Water. Loudoun Water, Prince William Service Authority, Virginia American Water, the town of Herndon, Fort Belvoir, and Dulles airport all obtain some or all of their water from Fairfax Water.

The Corbalis Water Treatment Plant also houses the Fairfax Water Quality Laboratory built in 2005 and using the state-of-the-art gas chromatography and laboratory equipment that reminded me that I studied chemistry in the Stone Age. The Water Quality Laboratory tests 15,000 samples of water each year and tested for 67,000 parameters including 3,240 samples tested throughout the year for coliform bacteria alone. Each and every month 270 samples are tested for coliform bacteria for the Virginia Department of Health, VDH.  All this testing is done to ensure that the water delivered to  their customers meets or exceeds all regulatory standards and that the water supply delivered to their 1.7 million customers is the best possible drinking water with today’s knowledge and technology.

The Water Quality Laboratory monitors the water from the Potomac River and Occoquan Reservoir throughout the water treatment process and at various points in the distribution system for almost 300 parameters including the Federal Safe Drinking Water Act, SDWA primary and secondary contaminants for which there exist maximum contaminants limits and also for a list of emerging contaminants such as Endocrine Disrupting Compounds (EDCs), Pharmaceuticals, and Personal Care Products (PPCPs) that have been found in water nationally. Fairfax Water tests their source and treated waters for a list of 25 substances, hexavalent chromium and perchlorate have recently been added to the list. In 2011 Fairfax water found minuscule traces (parts per billion or parts per trillion) of 2,4-D, TCEP, DEET, Monensin, Simazine, Atrazine,hexavalent chromium and perchlorate in the finished water.

The technology used for chemical analysis has advanced to the point that it is possible to detect and quantify nearly any compound known to man down to less than a nanogram per liter or parts per trillion (1/1,000,000,000,000). The guiding principal of toxicology is that there is always a dose below which no response occurs or can be measured. So if the concentration of the contaminant was low enough there would be no toxic reaction and a trace amount of a substance does not necessarily represent a health risk. Fairfax Water as one of the largest (top 25) water utilities in the nation gathers and provides some data to federal and state regulators that may determine the future changes in the SDWA. In the meantime, research has shown that using the combination of ozone and granular activated carbon filtration that is used by Fairfax Water is very effective in removing broad categories of personal care products and pharmaceuticals as well as the more dangerous Cryptosporidium organism from the source water. Though, no method of filtration is 100% effective all the time.

  

After Melissa Billman showed us the laboratories and their equipment, Jeanne Bailey led the plant tour. Ms. Bailey once worked in this plant, starting when the plant was brand new and delivered 50 million gallons of water a day in 1982. Now the Corbalis Water Treatment Plant can deliver 225 million gallons of water a day and is planned to be expanded to 300 million gallons a day years from now when the fourth and final phase of the plant is finally built. The plant was conceived and planned to be built in phases.  The Corbalis plant is the newer of the two Fairfax Water Treatment Plants. Water from Fairfax Water is distributed through approximately 3,200 miles of water mains to the county’s homes and businesses. On average, Fairfax Water produces 160 million gallons of water per day from both the Corbalis plant and the Griffith plant. The combined total capacity of both plants is 345 million gallons/day. The system must be sized to deliver the peak demand on a 100 degree day when everyone is doing laundry and watering their lawns and everything else we do with water on hot summer days.  To ensure the continuation of water supply during droughts, Fairfax finalized a regional drought response plan in 2001 that included a low flow allocation agreement with the members of the Interstate Commission on the Potomac River Basin, ICPRB. In addition, Fairfax bought the rights to 14 billion gallons of water from the Jennings Randolph Reservoir. 

The Corbalis Plant draws its water from the Potomac River four and a half miles away. There are two water intakes-one near the shore and the other mid-stream, which ever intake has better water quality is the one that is used.  Bars and giant screens on the pipes are used to prevent the intake of trash, debris and fish. Potassium permanganate (KMnO4) is added to the water at the intake to control taste and odors, remove color, prevent biological growth within the water treatment plant, and remove iron and manganese. The raw water is then pumped to the Corbalis plant where is treated in a series of slow and elegantly simple steps to produce clean and clear drinking water. 

  

Once at the plant the water is pumped to the first of a series of water chambers where the pH is adjusted by adding either caustic soda or sulfuric acid and the primary coagulant, polyaluminum chloride. This coagulant is used to remove small particles of dirt suspended in the water by causing them to stick to one another aided by the coagulant polymer. The water moves from the first water chamber where it is well mixed through a series of chambers (which are really just a series of open rectangular water pools) with slower and slower mixing to allow the particles to coagulate into larger and larger particles until dirt floc is formed. Finally, the water arrives in the sedimentation basins that are not mixed at all and the floc is allowed to settle to the bottom of basins by gravity where they are removed. The floc is thickened by the addition of a polymer, filtered, dewatered by pressure and ultimately used as a lovely agricultural soil amendment.

The next step in the water treatment process is ozonation, the infusing of the water with ozone gas and the first of two disinfection steps. This step was added at the Corbalis plant in 2000 and used this way is still very much leading edge in water treatment technology. Ozone is highly effective in eliminating the Cryptosporidium bacteria and other naturally occurring microorganisms present in water. Unlike ultraviolet and chlorine disinfection systems, there is no re-growth of microbes after ozonation. This step improves the taste and smell of the water. Ozonation also reduces the formation of trihalomethanes (chlorine breakdown products) because of the reduction of organic materials in the water before chlorination. Fairfax water converts liquid oxygen to ozone by an electrical discharge field created within a series of tanks. Viewed just right, you should be able to see the purple corona during the process, but I did not see it.

Ozonation is followed by filtration through granular activated carbon and sand. One cup of GAC has the surface area of about 25 football fields (1,300,000 square feet). Billions of pores in GAC absorb the organic substances removing them from the water and is very effective in removing biological and physical impurities that occur in broad categories of personal care products and pharmaceuticals as well as the more dangerous Cryptosporidium organisms from the water. Slow flow through the filter tanks improves the effectiveness of the filtration. The filter water wash, all runoff from the plant and the water from the dewatering process are reclaimed and returned to the raw water control chamber.

The final steps in the water treatment process is the second disinfection, fluoridation and the addition of a ammonium hydroxide to adjust the pH slightly to prevent corrosion of piping and fixtures in customer  homes to prevent the leaching of lead into water. Nine months of the year Fairfax Water uses chloramine as the final disinfection step. However, during April, May and June of every year Fairfax Water flushes the entire 3,200 miles of water main and uses chlorine during that time to disinfect the delivery network. Flushing the water system entails sending a rapid flow of water through the water mains. As part of the flushing program, fire hydrants and valves are checked and cleaned. Flushing of the water distribution system is performed to remove sediment in pipes and helps to keep fresh and clear water throughout the distribution system. Chlorine is used as the disinfectant during this time so that after the system is flushed, a chlorine residual is maintained in the distribution system to provide a persistent disinfectant to prevent the re-contamination of water before your water tap.

Building the plant in phases has allowed Fairfax water to modify their water treatment process and stay in the forefront of water treatment. Yet, Fairfax Water delivers water to their customers significantly below the national average cost of water, has the lowest retail water rates in the region and has a repair and replacement program that responds not only to the water main breaks, but is designed to replace the entire water supply and distribution system ever 75 years. Many thanks to Melissa and Jeanne for their time and a very interesting afternoon. 

Water Conservation and Household Use of Water in America

The United States as a nation possesses abundant water resources and has developed and used those resources extensively. The good news about water is that “on average” the United States uses less than 8% of the water that falls as precipitation within our borders annually. Unfortunately, precipitation varies from the average significantly on a regional basis.  With the exception of western, coastal regions of Washington, Oregon, and northern California, the western United States is arid and receives less annual precipitation than the rest of the nation, but water use is no longer tied to local precipitation. For example California uses 4,470,000,000 gallons of water per day for domestic consumption alone; it also uses 24,400,000,000 gallons of water per day for irrigation and would use more if it were available.

Traditional water management in the United States focused on moving or storing the country's abundant supplies of freshwater to meet the needs of users. The era of building large dams and conveyance systems has drawn to a close. The disruption of natural ecologies, environmental regulations, and the sheer cost of building the massive water projects has made them impossible. In the 21st Century, the regional limitations of the water supply and established infrastructure must be managed more effectively to meet increasing demands. "New" future supplies of water will come from conservation, recycling, reuse, and improved water-use efficiency rather than from ambitious development projects.

The future health and economic welfare of the Nation's population are dependent upon a continuing supply of fresh uncontaminated water. According to the US Geological Survey combined domestic private wellwater usage and public-supplied deliveries to homes totaled 29,400,000,000 gallonsper day in 2005, and “average” US citizen uses 98 gallons a day of water for domestic use, which includes, bathing and bathrooms, laundry, cooking, drinking and outdoor use. Outdoor watering in the drier climates causes domestic per capita use to increase in the driest and hottest climates. In Nevada, average domestic water use was reported to be 190 gallons/day per person, while in Maine they used on average 54 gallons/ per day. We have the most control over the amount of water we use in our homes and weather alone does not explain the different water usage rates. In Maryland average domestic water use was reported to be 109 gallons/day per person while in adjacent Virginia the average water usage was 75 gallons/day per person. Pennsylvania to the north uses an average of 57 gallons/day per person. The US Geological Survey who collected and compiled all this data and the estimates imbedded in them offers no explanation for the differences in domestic water use.  While I believe there are differences in water usage, I do not know the causes of the variation beyond the weather, but the age of the water fixtures can contribute to the differences.

There are tremendous differences in water consumption of appliances and fixtures based on their age and design. For example we all know about low-flush toilets which use 1.6 gallons per flush versus 5 gallons per flush for the older toilets. According to the 2001 Handbook of Water Use and Conservation by A. Vickers and published by WaterPlow Press in Amherst, MA the average person flushes the toilet 5.1 times a day. Before the advent of low flush toilet, flushing was the largest use of water for each person. If you have new toilets your daily water use for flushing would be 8.2 gallons versus 25.5 gallons for an older toilet. Compressor assisted toilets (commonly used in highway rest stops) only use 0.5 gallons of water and if widely adopted could reduce flushing use of water to 2.6 gallons per day per person. Other toilets that have separate flush cycles for fluid can also save water, and of course there is the California strategy of not flushing after only urinating to minimize the daily number of flushes. Changing your toilets and flushing behavior turns out to be the single most effective water conservation strategy. Thank goodness, there are now powerful flushing low flow toilets. 

The typical American uses the most water for flushing, showering, washing hands and brushing teeth, and laundry. Buying water efficient appliances and fixtures and changing behavior can significantly reduce our water use. For bathing and brushing teeth low flow faucets and showerheads and behavior modification (not running the water while you brush your teeth, shorter showers or not running the water while you lather up can save about a third of the water typically used for personal hygiene, reducing the typical 28 gallons a day to 19 gallons a day. Laundry is the second largest use of water after toilets. According to Dr. Vickers the typical American does 0.37 loads of laundry per person per day. A top loading washing machine uses 43-51 gallons per load while a full size front load machine uses 27 gallons per load and some machines have low volume cycles for small loads that use less. Replacing a top load washing machine with a front load machine saves 6-9 gallons of water per person per day or 24 gallons per load of laundry. A standard dishwasher uses 7-14 gallons per load while a water efficient dishwasher uses 4.5 gallons per load. Eliminating the watering of our ornamental gardens would significantly reduce water use especially in the most arid parts of the country where there is the most pressure on water supply. According to Dr. Vickers, by replacing appliances and fixtures with water efficient fixtures and eliminating outdoor use of water the typical American could reduce their water use to about 38 gallons per person per day. That is a significant water savings.

For people on public water supplies reducing domestic, indoor water use saves money on the water bill. The average cost of water nationally is reported to be under a penny a gallon, but that still adds up when you consider that going from 98 to 38 gallons of water per day would save 21,900 gallons of water per person per year. For my household on well water the concerns are different. My well draws fairly shallow for a Virginia well, my pump is at about 100 feet. The aquifer is unconfined and the water level will change with the seasons and drought. Natural groundwater levels usually reach their lowest point in late September or October. The highest levels tend to be during March and April, but this year was particularly dry until late April and it remains to be seen if this will be a dry year. Groundwater levels usually fall in May and continue to decline during summer as the trees and plants use the available water. Many well owners are very conscious of our water use because of the worry of the well going dry. Water conservation can help prevent a well from being pumped dry and can be used along with scheduled use to live with a low producing well.     

Black Spots on My House

If you have hundreds of little back spots on your home, porch, railing, retaining walls that look like overspray from coating your driveway or black paint, the real culprit is a white rot fungus in the mulch around the foundation of the house. The artillery fungus is very small about 1/10 of an inch across and are very hard to see in the mulch; however, the spores are very visible. The artillery or shotgun fungus, genus Sphaerobolus, is responsible for causing the tar like spots on light colored or reflective objects located in the immediate area. The artillery fungus is very common in the northeast, as well as many other parts of thecountry. The spore masses from the fungus are literally shot towards any reflective or bright surface or towards the light itself, so it tends to appear on windows, white siding, white cars and the stone retaining walls. The fungus appears most often on the northern side of the home. In my case the fungus covers the northeastern face of the house, leaving three sides untouched.

Artillery fungus is a wood-decay fungus that likes to live on moist landscape mulch and is most prevalent in the bagged bark and wood chip mixed type of mulch. The fungus tends shoot itspores during the cool, wet days of the spring and fall because sporulationdoes not occur above 77 degrees Fahrenheit. Artillery fungus (Sphaerobolus) spore masses may already be present at a site on old mulch, previously infested plant leaves, rabbit or deer droppings, decaying leaves, and grass and may reemerge each season. So until you eliminate the problem the fungus may reemerge every spring and fall. The artillery fungus grows better and produces more spores during wet years. The black spots (spores) are dormant, and pose no threat to the siding other than staining it, but sanding, scraping, or otherwise removing the spores, will allow them fall onto the ground and  infest any new foundation mulch. So if you are going to remove the spores from windows with a razor or other method, do it before you replace the mulch.

Control of this fungus can be very difficult. Even if I was willing to use chemicals, there are no fungicides for use against this fungus. Control consists mainly of removing infected mulch and plants. Infected mulch should be removed and new mulch put down in its place. Alternatively a new layer of mulch may be placed on top of the old to act as a barrier, but must be continually replaced. A study at Pennsylvania State University (home of the Nittney Lions) found that artillery fungus is least likely to occur in white pine bark and most likely to occur in wood chip and bark mixed mulch. I’m fairly sure that I introduced the fungus into my beds by buying mixed wood and bark mulch from the high school fundraiser for several years. Now I am trying to extinguish or control the fungus. According to the researchers artillery fungus seems to prefer wood as opposed to bark. Much of the mulch that we use today is recycled wood.  In addition, today’s mulches are finely-shredded to hold more moisture than the older coarsely ground mulches  

Since the fungus commonly occurs on dead trees, dead branches, rotting wood, etc., I am thinking of replacing my mulch with peat moss, but it is reportedly not sustainable because the peatbogs are fragile ecosystems. The researchers at Pennsylvania State University did not test peat moss; it is not a tree based product. Finely ground stones or nut shells might be another option. Recycled rubber mulches, are not a good solution to this problem. Research at Bucknell University indicates that rubber leachate from recycled car tires can kill entire aquatic communities of algae, zooplankton, snails, and fish. At lower concentrations, the leachates cause reproductive problems and precancerous lesions. Rubber mulches are flammable. Although some of the additives used in tire manufacture are toxic to rubber-degrading bacteria, the white-rot fungal species of which artillery fungus is a member can detoxify these additives allowing the breakdown of the rubber and the potential of leaching of toxic additives into the soil and the groundwater.

So, is there anything you can do about the damage to your home? It was almost a year before I noticed the spores on the northeast portion of my home and the number of spores have continued to increase despite my best efforts. Several attempts at removing the spores with various solutions failed. However, as can be seen in the pictures above I’ve had some limited success. The windows can be cleaned using a razor or putty knife, but I used the Mr. Clean Magic Eraser to remove the spores from around my entry and an on the windows. It was less successful on the textured surface of the vinyl siding leaving the ghost spots that are still visible. The picture below is of two sections of siding, I used the Eraser on the upper piece and the lower portion I left alone. It is not great, but a vast improvement.

Magic Erasers, Easy Erasing Pads and similar products all have the same key ingredient: melamine foam. Melamine foam erasers work well; but on surfaces that are painted, polished or easily scratched, they might damage the surface. (Do not use them on the body of a car!) My painted window frames and trim and front entry were fine, but yours might not be. It's recommended by the manufacture that you test the eraser on a small, preferably unnoticeable, portion of whatever you're looking to clean before you the sponge extensively on any surface. Melamine foam erasers wear out quickly and to remove the spores from my siding would essentially take hand rubbing of the entire side of the house and a carton (or ten) of the Magic Erasers. All this would have to be done before I put new bark mulch down on my beds. Not this year. 

EPA Regulates Air Releases from Fracked Wells

When natural gas is produced, some of the gas and other volatile substances present in the wells escapes. EPA released the first federal air rules for natural gaswells that are hydraulically fractured, specifically requiring operators of newfractured natural gas wells to use “green completion,” which is a series of technologies and practices to capture natural gas and other volatile substance that might otherwise escape the well during the completion period when the well transitioned from drilling through the completion string and fractured.

Much of the air pollution from fracked gas wells is vented when the well transitions from drilling to actual production, a multi-day process that involves running a pipe casing or a liner down the well to the production zone, and cementing it in place leaving perforations for flow. Once the completion string is in place, the final step is to fracture the well. Drilling requires large amounts of water to create a circulating mud that cools the bit and carries the rock cuttings out of the borehole. After drilling, the shale formation is then stimulated by hydro fracking, using 2-5 million gallons of water. For gas to flow out of the shale, all of the water not absorbed by the formation during fracking must be recovered and disposed of. Though less than 0.5% by volume, the proprietary chemicals represent 15,000 gallons in the waste water recovered from the typical hydro fracking job. The chemicals serve to increases the viscosity of the water to a gel-like consistency so that it can carry the propping agent (typically sand) into the fractures to hold them open so that the gas can flow.

The flowback fluid carries residual drilling muds, fracking fluid and gas. In many instances it is allowed to flow our of an open well and the fluid is placed in open ponds. The new rules will require this fluid to be captured by 2015, and flared before that. Open ponding of fracking fluids is eliminated. An earlier version of the rule limiting air pollution from gas wells would have required companies to install pollution-reducing equipment immediately after the rule was finalized, but in the final version there is a phase in period. Besides the new air pollution standards for oil and gas wells, the EPA also updated existing rules for natural gas processing plants, storage tanks and transmission lines.

According to the EPA , these new rules have received inter-agency feedback and provide industry flexibility as required under the recently signed Executive Order on Natural Gas Development. Agencies involved include the departments of Defense, Interior, Agriculture, Commerce, Health and Human Services, Transportation, Energy and Homeland Security, as well as the EPA, Council on Environmental Quality, Office of Science and Technology Policy, Office of Management and Budget, and National Economic Council.

EPA Announces Record US CO2 Emissions

This week the U.S. Environmental Protection Agency (EPA) announced the release of the annual U.S. greenhouse gas inventory. Overall the report shows US emissions of greenhouse gases increased by 3.2% in 2010 from 2009, but are still 3% below 2008 levels. Total gross US emissions of the six main greenhouse gases in 2010 were equivalent to 6,822 million metric tons of carbon dioxide equivalent and according to the EPA represents 18% of world CO2 equivalent emissions based on the InternationalEnergy Agency, IEA, estimates. Net (of the CO2 sinks of our forest land) US emissions of CO2 are reported to be 5,747 million metric tons down 4% since 2008. It is interesting to note that while worldwide CO2 emissions and US CO2 emissions were both down in 2009 from 2008 levels, worldwide CO2 emissions increased 5% from 2008 levels while US CO2 emissions are still 4% below 2008 levels. In the past 20 years, the US is estimated to have increased CO2 equivalent emissions by 10% as our share of worldwide emissions has fallen.  The peak of CO2 emissions in the US was 2007.

Greenhouse gases include water vapor, carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons and sulfur hexafluoride. The US collects data and estimates CO2 equivalent emission because in 1992, the United States signed and ratified the United Nations Framework Convention on Climate Change, UNFCCC.  The UNFCCC dictates the methodology to calculate and track greenhouse gasses looking only at CO2, CH4 and N2O. Stratospheric ozone depleting substances, CFCs, HCFCs, and halons are not required to be included in national greenhouse gas emission inventories, they are tracked under another treaty.

Naturally occurring greenhouse gases include water vapor, carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and ozone (O3). Several classes of halogenated substances that contain fluorine, chlorine, or bromine are also greenhouse gases, but they are, for the most part, solely a product of industrial activities. Although the direct greenhouse gases CO2, CH4, and N2O occur naturally in the atmosphere human populations have changed their atmospheric concentrations by burning fossil fuel, removing forest cover, breathing, raising animals. It is reported by the IEA that concentrations of these greenhouse gases have increased globally by 39%, 158%, and 19%, respectively since 1750.

TheInventory of U.S.Greenhouse Gas Emissions and Sinks: 1990-2010 is the latest annual report that the United States has submitted to the UNFCCC, as it tries to orchestrate intergovernmental efforts to control greenhouse gas emissions. EPA prepares the annual report in collaboration with experts from multiple federal agencies and now with the data from the EPA’s Greenhouse Gas Reporting Program launched in October 2009, requiring the reporting of carbon dioxide data from large stationary emission sources, as well as suppliers of fuel that would emit greenhouse gases if used, the US estimates of greenhouse gases should be more accurate. Of the greenhouse gasses generated in the US 33% is from the generation of electricity and 26% is from transportation.

The EPA and the Department of Transportation’s NationalHighway Traffic Safety Administration (NHTSA) new millage and emissionstandards for automobiles and light trucks for model year 2012 through 2016 require these vehicles to meet an estimated combined average emissions level of 250 grams of carbon dioxide (CO2) per mile in model year 2016, equivalent to 35.5 miles per gallon (mpg) if the automotive industry were to meet this CO2 level all through fuel economy improvements. In March the EPA announced the Carbon PollutionStandard for NewPower Plants that limits the amount of CO2 that can be produced for each megawatt of electricity produced.  That standard effectively changes the fuel of choice for all future power capacity additions to natural gas, nuclear, or the renewable category (with government subsidies). All existing plants and currently permitted and built in the next 12 months will be grandfathered and exempt from this new rule for a period of time.  Reductions in CO2 generation from power plants will not improve human health. CO2 is vital for photosynthesis and the environment and has no direct negative human health effects. Humans produce CO2 and exhale it so it is present at levels much exceeding atmospheric concentrations in the lungs.

 In the past year EPA has issued two other regulations targeted at coal fired power plants, EPA’s Cross-State Air Pollution Rule, CSAPR, and Mercury and Air Toxic's Standard, MATS.  CSAPR which requires reductions of sulfur-dioxide and nitrogen-oxide emissions in coal fired plants was made final in July but at the end of last year,the U.S. Court of Appeals District of Columbia Circuit granted a stay to the implementation of the CSAPR pending resolution of the legal challenges. MATSregulates mercury, arsenic, acid gas, nickel, selenium, and cyanide and was finalized on December 21. 2011. Both of these regulations are anticipate to have direct human health benefits.  Nonetheless, appears that CO2 and to a lesser extent the other greenhouse gases are the EPA’s primary focus.  However as can be seen above, US CO2 emissions is growing slowly if at all and accuracy in data collection, and increased US regulation of CO2 emissions from power plants and automobile millage standards is not going to slow world CO2 emissions growth.   

  

The Rural Crescent an Essential Part of Our Green Infrastructure

At the regular March meeting of the Prince William County Board of Supervisors while considering requests for exceptions to the comprehensive plan, Supervisor Martin Nohe supported by the other county Supervisors seemed to feel that it was time to reconsider some of the planning and development decisions that had been made in the past and asked for staff to produce an analysis of the usefulness of the Rural Crescent in achieving those goals. The request was made by Supervisor Nohe to Prince William County staff and noted in the minutes.

The Rural Crescent was created in 1998 and has been chipped away at with exception requests every year. Higher density development means money to developers and landowners. There is much passion when money is on the table. The Rural Crescent in Prince William County was originally intended as an urban growth boundary for the county designed to preserve our agricultural heritage and force redevelopment along the Route 1 corridor rather than Greenfield development in the remaining rural areas. Maintaining the emphasis on redevelopment of areas with preexisting infrastructure would allow Prince William County to improve storm water management, achieve nutrient and sediment reductions for the EPA mandated TMDL, revitalize older areas of the county and preserve the Greenfields. The Rural Crescent may have started with different intentions; but today the Rural Crescent is about water, groundwater and ecosystem preservation.

Supervisor Nohe’s interest in transforming the 80,000-acre rural crescent where development has generally limited to one home per 10 acres with no access to public sewer is of great concern. Even though I believe that Supervisor Nohe is interested in moving towards sustainable community concepts, high density communities utilizing the strategies of Low Impact Development, LID, which include dedicated open space will not guarantee the preservation of our ecosystem and water. When development disturbs more than 10% of the natural land by covering surfaces with roads, driveways, walkways, patios, and homes the natural hydrology of the land is disturbed, irreparably disturbed. These developments while much better than traditional developments still disturb more than half the land area by significantly increasing allowed building density.

 While it has been demonstrated that LID strategies can reduce the impact of development, there is no demonstrated strategy of how communities can control and maintain natural storm water features and preserve and maintain the safety and ecology of preserved open space. There are no regional groundwater studies, regional ecosystem pans and no budgets for maintaining the open space.  Access control and prevention of improper use (underage drinking, drug use and sale,  other illicit activities, dirt bike racing) addressing deer population management and hunting adjacent to high density homes, litter and trash removal, maintenance of natural landscapes and supervision all cost money and time. No legal structures exist that guarantee open spaces will not be developed in the future to defray maintenance costs.  Why the Rural Crescent was formed is less important than understanding that the Rural Crescent provides a significant portion of our green infrastructure to our community.  

Green infrastructure connects the still intact habitat areas through a network of corridors that provide for wildlife movement and trails as well as pathways for pollinators. Maintaining intact, connected natural landscapes is essential for basic ecosystem and watershed preservation to ensure that there will always be clean air and water in Northern Virginia. Maintaining a tree canopy and controlling runoff to prevent stream bank erosion and water quality impairments and maintaining adequate water flows through groundwater and surface recharge are vital to ensuring safe water supplies, water recreation and the ecological integrity of the region. The Northern VirginiaRegional Commission (NVRC) has developed a Conservation Corridor PlanningProject which is a regional effort to identify essential green infrastructure and help area governments to avoid the mistakes of the past and maintain the few remaining green corridors along the rivers and reservoirs in Fairfax and integrate green infrastructure planning into the future development planning of Prince William and Loudoun counties.  

According to NVRC there are three priority regional conservation corridors in Prince William County.  Bull Run Mountain and Catoctin Mountain corridor is a north-south corridor connecting the foothills of the Blue Ridge Mountains in Northern Virginia.  The corridor provides significant intact habitat for Northern Virginia wildlife.  North of Leesburg, the corridor is the karst terrain of Loudoun underlain by limestone, and highly susceptible to pollution that provides a significant ground water recharge.

Karst aquifers are highly vulnerable to contamination. This vulnerability results from: sinkholes, widened flow paths, and rapid velocities of ground water and contaminants. Contaminants can be transmitted quickly from entry in a sinkhole to wells and springs in the vicinity. Sinkhole creation, sinkhole flooding, and groundwater contamination are the major hazards associated with karst terrain, and unlike other natural hazards they are chronic in nature. South of Route 50 the Bull Run Mountain ridge is the location of a significant area of recharge for the groundwater that ultimately maintains and feeds Bull Run and the Occoquan River. This area is part of a fractured rock system with limited overburden and no natural attenuation. A polluted plume could be carried for miles without dilution.

The second priority conservation area is begins at the Bull Run Mountains and heads east across Route 15 to Manassas covering the land between Route 50 and 29 to the confluence of the Occoquan River with Belmont Bay. This corridor is rich in water and environmental resources that ultimately deliver drinking water to over one million Northern Virginia residents. The Occoquan Reservoir, one of the country’s first water reclamation facilities where sewage treatment water is returned to provide water recreation. The western portion of the area is part of the Culpeper Basin Important Birding Area and the Culpeper Basin Groundwater Aquifer. Preventing water contamination and ensuring adequate groundwater recharge are vital to ensuring safe water supplies, recreation opportunities and the ecological integrity of the region.

The third priority conservation area is the Potomac Gorge and Quantico Corridor, the greenbelt that connects Prince William National Forest Park with Manassas Battlefield. This area includes large tracks of undeveloped private land. The western portion of the Rural Crescent was not identified by NVRC as a high priority conservation area because they failed to consider the importance of the groundwater aquifer. The Culpeper basin is part of a much larger PiedmontGeologic Province and has only begun to be studied thanks to the carefulgroundwater measurements taken by Loudoun County as excessive development ofthe western part of the county began to impact water supplies.  Groundwater quantity and quality in our region impacts not only groundwater wells, but stream flow and recharge to the surface water. In short all the drinking water in Prince William County. Groundwater recharges at various rates from precipitation and other sources of infiltration. The recharge is not spread evenly across the land. Pave over the land, change surface flow and infiltration and groundwater recharge are reduced.

Important regional waterways, such as Goose Creek, Bull Run, the Potomac River and Occoquan Reservoir thrive because they are shaded by trees and vegetation that filter stormwater, prevent erosion, and facilitate ground water recharge and moderate temperatures. Green infrastructure maintenance ensures the forested buffers are maintained and enhanced over time, protecting public health and water quality. Maintaining and enhancing forested buffers near Northern Virginia’s waterways requires focus on how to maintain and protect these ecological resources. The EPA has identified nitrogen, phosphorus and sediment as the three primary pollutants that must be reduced to restore the health of the Chesapeake Bay and its tributaries. They have mandated to Virginia and the other Chesapeake Bay Watershed states and Washington DC an approximate 25% reduction in these pollutants. A wide range of approaches can address these impairments, including reducing runoff and restoring stream banks and buffer areas. Adding more development in the Rural Crescent will not reduce the current level of sediment and nutrient pollution, and will not assure our water resources and ecology. 

Emerging Contaminants in Your Drinking Water

Chemicals are everywhere, they exist in pharmaceuticals, household products, personal care products, plastics, pesticides, industrial chemicals, human and animal waste; they are in short, all around us. These chemicals include organics, inorganic, polymers, complex reaction products, and biological materials. The technology used for chemical analysis has advanced to the point that it is possible to detect and quantify nearly any compound known to human kind down to less than a nanogram per liter or parts per trillion (1/1,000,000,000,000). This enhanced analytical ability has allowed scientists to discover that trace levels of pharmaceuticals, potential endocrine disrupting compounds (EDC) and other emerging contaminants exist in much of our surface water and is appearing in some groundwater and persists in the water through conventional and some advanced treatments to also appear in our finished drinking water. The list above have all been found by testing performed by Fairfax Water.

All water on earth is part of the hydraulic cycle and is reused over the course of time. These traces of chemicals have managed to slip through the earth’s natural filtration and some of them through treatment systems to be identified in finished drinking water at extremely low levels. Finished and source water (as well as food and beverages) have been found to have low levels of these emerging chemicals, but whether this low level of exposure can cause any health effects or developments effects is unknown. Some of the emerging chemicals are or maybe endocrine disruptors, a class of chemicals that can mimic, block, or otherwise alter animal hormone responses. Endocrine disruptos can sometimes affect reproduction, development, and behavior, this is actually, how some pest control treatments are designed to work. A diverse group of chemicals called endocrine disrupting chemicals (EDCs) come from a variety of sources. These chemical have diverse molecular structures. BPA is just one of these chemicals. These chemicals become of great concern when they are discovered to be potential human endocrine disruptors as DDT, dioxin, PCBs and the drug DES were found to be in the past. Traces of endocrine disrupting chemicals are seemingly found in every part of our world, including dust, soil, water, air, food, manufactured products, wildlife, and even ourselves.

 Findings in the Fourth National Report on Human Exposure to Environmental Chemicals by the Center for Disease Control (CDC) in December 2009 and updated in 2012 indicate widespread exposure to some commonly used industrial chemicals. This exposure may have existed for decades but our ability to identify parts per trillion has allowed us to become aware of the ubiquitous exposure. The CDC measured 212 chemicals in the blood and/or urine of the participants. The samples were collected from participants in CDC's National Health and Nutrition Examination Survey (NHANES), which is an ongoing survey that samples the U.S. population every two years. Each two year sample consists of about 2,400 people. What the report found was widespread exposure to some chemicals throughout the population tested. The implications of this ubiquitous exposure are unknown, but of concern. The detection of a chemical in a person’s blood or urine does not mean that it will cause health effects or disease. The guiding principal of toxicology is that there is a relationship between a toxic reaction (the response) and the amount of poison received (the dose). An important assumption in this relationship is that there is almost always a dose below which no response occurs or can be measured. So if the concentration of the contaminant was low enough there would be no toxic reaction, but that principal is being tested with endocrine disruption and advances in analysis.

The occurrence of intersex fish in the Potomac River, and in other areas of the US resulted in Congressional hearings in the fall or 2006 to inquire about the “State of the Science on EDCs in the Environment,” as well as the US EPA’s activities associated with EDCs. The hearings resulted in a White Paper; “AQUATIC LIFE CRITERIA FOR CONTAMINANTS OF EMERGING CONCERN” and validation of analytical methods. In 2009, a final list of 67 chemicals and the schedule for issuing Test Orders for Tier 1 screening was issued. EDSP Tier 1 screening requires a battery of assays tests to identify chemicals that have the potential to interact with the estrogen, androgen, or thyroid hormonal pathways. The battery consists of 11 assays that have been developed and validated by the Office of Chemical Safety Pollution and Prevention. EPA intends to evaluate the results of the Tier 1 screening assays to determine whether or not a chemical has the potential to interact with the estrogen, androgen or thyroid hormonal pathways and to assess the need for Tier 2 testing. The work proceeds slowly.

 Meanwhile, water utilities are left not knowing how to address findings of emerging contaminants in their source and finished drinking water. A study conducted by the Water Research Foundation concluded that using a combination of ozone and granular activated carbon in addition to coagulation, sedimentation, filtration and disinfection is effective in removing some of the broad categories of EDCs, personal care products and pharmaceuticals found in drinking water. The American Water Works Association Research Foundation developed an Acceptable Daily Intake level for many of the emerging contaminants that are being found in drinking water supplies. An Acceptable Daily Intake level or ADI is a measure of the amount of a specific substance in food or drinking water that can be ingested orally over a lifetime without an appreciable health risk. Unfortunately, the reference doses ADI levels were the historic levels established by the EPA based on non-endocrine toxicity and cancer risk. These screening levels were not developed to determine whether certain substances may have an effect in humans on estrogen, androgenic or thyroid-related pathways, but were developed to protect populations from acute toxicity or cancer.

 In addition to finding intersexed fish in the Potomac, researchers have found male amphibians with ovaries and female frogs with male genitalia and frogs with six legs and other mutations. The endocrine system of fish bears some similarity to the human endocrine system, but we do not live our lives in the waters of the Potomac. Two million people rely on the Washington Aqueduct for their drinking water and millions of people in other parts of the country drink source water with similar observed occurrences of endocrine disruption. The impact on human life and the ecosystem of these emerging contaminants is not known, but according to Dr. Robert Lawrence of the Johns Hopkins School of Public Health and other scientists there is the potential to for humans to develop premature breast cancer, have problems with reproduction, and develop congenital anomalies of the male genitalia. Some believe these kinds of impacts are happening at a broad and low level in society so that the occurrence is not alarming to the general public or easily noted without detailed statistics, other scientists can find no measurable risk. We can no longer live in the happy world where we believed that our water was contaminant free. In truth, we do not know these trace chemicals are hazardous and how pure water (and food) needs to be. More research is needed on these emerging contaminants. Resources are limited and we need to make wise use of our economic and natural resources that is impossible without information.